本文实例讲述了PHP实现将上传图片自动缩放到指定分辨率，并保持清晰度封装类。分享给大
本文实例讲述了PHP实现将上传图片自动缩放到指定分辨率，并保持清晰度封装类。分享给大家供大家参考，具体如下：
class AutoImage{
private $image;
public function resize($src, $width, $height){
//$src 就是 $_FILES['upload_image_file']['tmp_name']
//$width和$height是指定的分辨率
//如果想按指定比例放缩，可以将$width和$height改为$src的指定比例
$this->image = $src;
$info = getimagesize($src);//获取图片的真实宽、高、类型
if($info[0] == $width && $info[1] == $height){
//如果分辨率一样，直接返回原图
return $src;
}
switch ($info['mime']){
case 'image/jpeg':
header('Content-Type:image/jpeg');
$image_wp = imagecreatetruecolor($width, $height);
$image_src = imagecreatefromjpeg($src);
imagecopyresampled($image_wp, $image_src, 0, 0, 0, 0, $width, $height, $info[0], $info[1]);
imagedestroy($image_src);
imagejpeg($image_wp,$this->image);
break;
case 'image/png':
header('Content-Type:image/png');
$image_wp = imagecreatetruecolor($width, $height);
$image_src = imagecreatefrompng($src);
imagecopyresampled($image_wp, $image_src, 0, 0, 0, 0, $width, $height, $info[0], $info[1]);
imagedestroy($image_src);
imagejpeg($image_wp,$this->image);
break;
case 'image/gif':
header('Content-Type:image/gif');
$image_wp = imagecreatetruecolor($width, $height);
$image_src = imagecreatefromgif($src);
imagecopyresampled($image_wp, $image_src, 0, 0, 0, 0, $width, $height, $info[0], $info[1]);
imagedestroy($image_src);
imagejpeg($image_wp,$this->image);
break;
}
return $this->image;
}
}